Complete pipelayer

ABSTRACT

Pipe to be laid underground is laid on the ground connected. Vibrating rippers straddle the pipe and shatter the ground on either side of the path where the pipe is to be laid. The rippers are tied together so they have no resultant horizontal vibration, but each is free to vibrate vertically. The rippers are vertically vibrated out of phase. A chute behind the rippers push the shattered soil laterally and guide the pipe to the bottom of the trench thus formed. The front of the chute has doors which open to permit the chute to be pushed down over the pipe and to be picked up from the pipe, but which are closed during operation.

United States Patent [1 1 Rogers [111 agma [451 Feb. 5, 1974 1 COMPLETE PIPELAYER [52] US. Cl 61172.6, 37/193, 172/40 [51] Int. Cl. A0lb 3/64, F161 1/00 [58] Field of Search 61/726, 72.5, 72.1, 72.4;

172/40; 37/DIG. 18, 193

[56] References Cited UNITED STATES PATENTS 3,561,539 2/1971 Evans 172/40 3,357,498 12/1967 Higley.... 172/40 2,909,134 10/1959 Kniefel... 61/726 2,144,063 1/1939 Irvin 61/724 Primary Examiner-Jacob Shapiro Attorney, Agent, or Firm-Wendell Coffee [57] ABSTRACT Pipe to be laid underground is laid on the ground con nected. Vibrating rippers straddle the pipe and shatter the ground on either side of the path where the pipe is to be laid. The rippers are tied together so they have no resultant horizontal vibration, but each is free to vibrate vertically. The rippers are vertically vibrated out of phase. A chute behind the rippers push the shattered soil laterally and guide the pipe to the bottom of the trench thus formed. The front of the chute has doors which open to permit the chute to be pushed down over the pipe and to be picked up from the pipe, but which are closed during operation.

25 Claims, 9 Drawing Figures PATENTEDFEB 5W 3.789.614

sum 10! 5 PATENTEDFEH 51974 SHEEUHIFS PATENTEDFEB sum SHEETSUFS COMPLETE PIPELAYER CROSS-REFERENCE TO RELATED APPLICATIONS Presently, applicant has pending application Ser. No. 262,478 entitled FISHTAIL RIPPER, which involves a vibrating plow, but no priority is claimed.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to earth engineering and more particularly to pipelaying wherein the pipe is flexed as it is laid in subterranian position by a machine which advances along the path.

The soil is loosened for the layer with a pair of vibrating rippers.

2. Description of the Prior Art In the field of vibrating plows, it is known that a plurality of vibrators may be included in a single unit to achieve vibration in one direction only. Examples of such teaching are SHELTON U.S. Pat. No. 3,425,496, and my own U.S. Pat. Nos. 3,448,813 and 3,451,487.

Also, it is known that where there is a plurality of plows, some of them can be vibrated out of phase with the others so the total resultant vibration transmitted to the frame is very small or absent. My previous U.S. Pat. Nos. 3,336,985 and 3,627,056 are examples of such teaching.

Also, in laying cable or small diameter flexible tubing or pipe, it has been known that a vibrating plow could be used with a guide chute attached thereto, see my U.S. Pat. No. 3,508,411.

Examples of prior patents in this regard are given below. This listing is meant to be exemplary and not exhaustive. However, to the best of my knowledge, according to the prior art, the chute has followed along in a trench made by the opening ripper. Also, all of these were relatively narrow, i.e., for cable about two to four inches in diameter.

Garlinger U.S. Pat. No. 2,118,553

Hash U.S. Pat. No. 2,722,181

Ede U.S. Pat. No. 3,250,077

Kniefel U.S. Pat. No. 3,313,115

Davis U.S. Pat. No. 3,363,423

SUMMARY OF THE INVENTION New and Different Function I have solved the problem of laying heavier, less flexible pipe of larger diameter by first assembling the pipe on top of the ground and then straddling the pipe and shattering the earth with vibrating rippers. The rippers themselves do not form the trench, but the trench is formed behind the rippers with the front of the chute. The trench is held open by extending walls of the chute. The soil is pushed to either side by the chute rather than excavated to the surface. After the pipe is in place, the earth is permitted to close in around the laid pipe.

Also, with the rippers, two rippers are yoked together; thereby, the yoke absorbs all vibration except vertical and permits each to vibrate vertically. However, they are timed so the vertical vibrations are out of phase and, therefore, at the center of the yoke connecting the rippers, there is no vibration. Therefore,

the center part of the yoke may be used as a push-down point to push the plows down into the earth.

Thus, I have solved the problem of providing general purpose, vertically vibrating plows or rippers whereby push-down pressure may be'applied to the plows. This achievement permits the general purpose rippers to be directly tractor mounted if desired. In tractor mounted model, weight of the tractor may be transferred to the plows at the center of the yoke while no vibration is transferred back to the tractor.

When the plow is tractor mounted, the vibrator may be driven by hudraulic power, or direct mechanical drive from the tractor. For an alternative, an internal combustion engine may be mounted on a non-vibrating platform above the yoke and be a portion of the weight to be applied to the yoke and rippers, somewhat similar to JOHNSON U.S. Pat. No. 3,502,152.

In addition to providing a non-vibration point at the center of the yoke, the alternate vibration has the desirable function of preventing a build up of earth between the rippers as sometimes occurs with two adjacent rippers which do not vibrate or two adjacent rippers which vibrate as a unit.

OBJECTS OF THIS INVENTION An object of this invention is to lay pipe.

Another object is to provide vibrating plows whereby push-down pressure may be applied to the plows.

Other objects are to achieve the above with a device that is sturdy, compact, durable, simple, safe, efficient, versatile, and reliable, yet inexpensive and easy to manufacture, operate, and maintain.

Further objects are to achieve the above with a method that is versatile, rapid, efficient, and inexpensive, and does not require skilled people to adjust, operate and maintain.

The specific nature of the invention, as well as other objects, uses, and advantages thereof, will clearly appear from the following description and from the accompanying drawing, the different views of which are not necessarily to the same scale.

BRIEF DESCRIPTION OF THE DRAWING:

FIG. 1A is a side elevational view of the plow section of a first embodiment of the invention with some of the parts broken away and in section for clarity taken substantially on line 1-1 of FIG. 2.

FIG. 1B is a side elevational view primarily showing the chute section of the machine with some of the parts broken away and in section for clarity.

FIG. 2 is a top elevational plan view of the vibrating plows of FIG. 1A and their beams and the forward portion of the outer frame.

FIG. 3A'is a top plan view to an enlarged scale showing the back of the vibrating plow assembly of FIG. 1A and the front of the chute.

FIG. 3B is a top elevational view of the rear portion of the chute.

FIG. 4 is a rear elevational view schematically representing the vibrators and their relationship to the plow and the linkage means of FIG. 1A.

FIG. 5 is a side elevational view of a portion of the plow section of a secondembodiment where pushdown pressure is applied to the plows.

FIG. 6 is a sectional view taken substantially on line 6 -6 of FIG. 5.

FIG. 7 is a top elevational view of the embodiment shown in FIG. 5. i

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly to the drawing, (FIGS. 1 through 4), it may be seen there a large vibrating plow having two laterally disposed earthworking implements or rippers 10. Each of the rippers is rigidly attached to its draft beam 12. Both draft beams 12 are connected by link 14 to forward anchor point 16 of outer frame 18. The outer frame 18 has hitch means 20 at the forward end of the anchor point 16 by which the outer frame may be connected to the draft vehicle (not shown). The outer frame 18 is supported by pneumatic wheels 22.

A pair of steel wheels 24 are attached to the forward anchor point 16 by crank arm 26 and hydraulic cylinder 27 so the forward anchor point 16 may be raised and lowered. Also, the steel wheels 24 dampen any vibration at this point because of its firm engagement with the ground.

Prime mover in the form of internal combustion engine 28 is also mounted upon the outer frame 18.

Reference is made to my prior U.S. Pat. Nos. 3,508,411 and 3,396,804 for details of the outer and inner frame construction.

Each of the draft beams 12 is supported by a pneumatic tire on wheel 30 which is mounted upon crank arm 32 so that operation of hydraulic cylinder 34 will raise and lower the beam 12 and thus the ripper 10. In addition, for raising the ripper completely out of the ground for transportation, cable 36 and cylinder 38 are provided, similar to that shown and described in my issued U.S. Pat. No. 3,508,411. The draft beams 12 are connected together by yoke or linkage means 40. This linkage means 40 is shown as pitman 42 which is connected by pivot bolts 44 to the rear of each of the draft beams 12 or rippers 10. Therefore, it may be seen that each draft beam 12 may, within limits, move vertically with respect to the adjacent draft beam, but cannot move horizontally except as they both move together.

It will be understood that the pitman 42 is shown as merely being exemplary of one type of linkage which could be used to connect them. I contemplate that other type links could be used so long as they fulfill the function of permitting vertical motion as between the two draft beams 12, but prohibiting separate horizontal movement.

Each draft beam 12 carries thereon rotary vibrator 46 as schematically illustrated in FIG. 4. It will be noted in FIG. 4 that the rotary weights of the vibrators 46 are 180 out of phase and shown to be rotating both in a clockwise direction. Therefore, analysis will show that if they are driven in such manner, the beams 12 will be urged to vibrate in opposite directions at all times. I.e., when one beam is urged downward, the other beam will be urged upward, which motion is permitted. Also, when one beam 12 is urged to the right, the other beam 12 is urged to the left, however, the linkage 40 between them prohibits this motion and this motion is completely balanced out as between the two beams 12. Therefore, there is little or no resultant vibration to the outer frame 18. What resultant vibration there is to the outer frame is largely dampened out by the forward steel wheel 24.

The rotors or weights of vibrator 46 are each driven by a tumble shaft 48. Each tumble shaft has expansion joints and universal joints to permit considerable movement between gear box 50 and the elements of vibrator 46. The gear box 50 is mounted on the outer frame 18 and is driven by power shaft 52 from the prime mover 28. The details of the gear box 50 are not shown, but are such that it drives each of the tumble shafts 48 at the same speed and in the same direction so the rotors of the vibrators 46 remain timed as described.

The two rippers 10 are spaced apart a distance so they may straddle pipe 54 which is to be laid underground.

Therefore, it may be seen that with the vibrating plow section in operation (straddling the pipe 54), the soil is thoroughly shattered and loosened beneath the pipe. It will be understood that the pipe 54 is an extending pipeline with the various sections welded or attached together so that it extends for considerable distance. The ripper plows 10 extend to a depth the pipe 54 is to be laid.

Chute 60 has as a principal part thereof two vertical plates 62 which form side retaining walls for the trench which is formed. Side plates 62 are rigidly connected together by top plate 64. Triangle plates 66 are welded to the top upper outside edge of the vertical plates 62 and form a basis for vertically spaced pins 68. The vertical spaced pins are placed upon the outer frame 18 with the same spacing as the spacing between the pins 70. The pins 68 and 70 are connected by parallel-link bars 72. Hydraulic cylinder 74 extends between a point on the outer frame and the parallel-link bars 72 as seen in FIG. 1A; therefore, by operation of the hydraulic cylinder 74, the chute 60 may be raised and lowered.

Door 76 is hinged by vertical hinges 78 to the front of each of the vertical plates 62. Bell crank 80 is connected to the top of each of the doors 76 so operation of hydraulic cylinder 82 causes the doors to open and close. They are shown in the closed position. It will be understood by those skilled in the art that operation of the hydraulic cylinder 82 would cause them to open.

Nylon contoured roller 84 is connected at the forward portion between the vertical plates 62 approximately the ground level when the chute is in operation. Although not shown, it is attached by pins for ready removal or it may be itself mounted upon a door within an opening in the side of one of the vertical plates 62 so that by operation of a hydraulic cylinder, the contoured roller 84 could be swung to the outside and inside the chute 60 as will be explained later.

Through about midway of the length of the vertical plate 62 is mounted a second contoured roller or pushdown roller 86. The push-down roller 86 is mounted upon pusher arm 88, which is pivoted at ears 90 at the top of the vertical plates 62 and an extension of the pusher arm 88 is attached to hydraulic cylinder 92.

Forward contoured roller 94 is connected at the front of the chute 60 and is attached by arm 96 to the forward front of the top plate 64.

OPERATION The draft vehicle straddles the pipeline 54 to be laid. The wheels 24 straddle the pipe. The rippers 10 likewise straddle the pipeline 54. By proper operation of hydraulic cylinders 38 and 34, the rippers 10 are lowered into the ground, straddling the pipe 54. Operation of the prime mover 28 causes them to vibrate, shattering the soil.

With the doors 76 open, the chute 60 is placed over the pipe 54 straddling it. The chute is forced into the ground by hydraulic cylinders 74. The front contoured lifter roller 84 is removed. When the chute 60 is forced into the ground so that the position of the lifter roller 84 is below the level of the pipe, the first step is accomplished. The lifter roller 84 is connected in position so the pipe 54 rides over the front of the doors 76; therefore, the lifter roller is about, or slightly higher, the levelof the front of the doors 76. After the roller 84 is in place and the pipe 54 is above it, operation of the door hydraulic cylinder 82 closes the door 76. The operation of the hydraulic cylinder 92 positions the push-down roller 86 on top of the pipe 54 so the pipe 54 is pushed down. Forward roller 94 prevents the pipe forward of the doors from angling up too high so that it is hammered or beat by the vibrating beams 12.

Then, a forward movement of the draft vehicle (not shown) causes the rippers to shatter the ground and the doors 76 push the shattered soil to either side, thus forming a trench. The doors 76 thus act as a moldboard or plow to mold the soil, pushing it to either side and forming a trench. The pipe 54 is pushed to the bottom of the trench by the push-down roller 86 and the vertical plates 62 prevent the soil from falling to the bottom of the trench before the pipe 54 is pushed to the bottom of the trench. However, once the pipe is pushed to the bottom of the trench, the vertical plates 62 terminate and the soil is permitted to fall on top of the pipe, it now being positioned properly in place.

Therefore, it may be seen thatl have provided a machine to completely lay a large pipe underground.

As illustrated if FIGS. 5, 6, and 7, a modification is shown somewhat schematically. in this modification, ears 100 are attached on the outside of each of the draft beams 112. Yoke 142 is pinned to the ears by pins 144 which are aligned with the direction of draft. The two yoke plates 142 are used so they straddle the ears 100. At the top, centered between the beams 112, push-down hydraulic cylinder 102 extends from the outer frame not shown in these three drawings) to pin 104. The pin 104 is parallel to the pins 144. Therefore, extension of the push-down cylinder 102 causes a downward thrust or pushing down upon pin 104, which is transmitted through the yoke 142 and the pins 144 to the ears 100 which are connected to the draft beams 112. Since the rippers 110 are rigidly attached to the draft beams, downward pressure is applied to the rippers 110. A vibrator 146 carries a single eccentric rotor or weight which is timed to rotate at the same direction of 180 out of phase with the other rotor. Therefore, the yoke 142 prevents any horizontal motion independently as between the twobeams 112, but permits each to have vertical vibration. Since the vertical vibration is equal and opposite, at the center of the yoke there is no vibration and, therefore, the push-down cylinder is not subject to vibration nor does it transmit vibration to the outer frame.

Another modification could be the inclusion of 'a non-vibrating center bean (not illustrated). This center beam would be approximately the length of the beams 112 and attached with the beams 112 to the outer frame at front (or to the tractor if the plow were directly mounted). Links corresponding to yoke 142 would connect the center beam to each of the vibrating beams 112. The center beam would be beneficial for adding weight bars and for raising and lowering the ripper beams 112, and the adding of other pertinent equipment.

It will be understood that the purpose of this specification and drawing are to enable those skilled in the art to manufacture and use a pipelayer according to this invention. Many details of construction, such as bracing on the frame or, for example, cross-bracing on the parallel arms 72, have not been shown in detail, and other parts such as the internal combustion engine 28 are shown by schematic representation. However, from this specification, those skilled in the building of heavy machinery will be able to make and use this invention.

The embodiments shown and described above are only exemplary. I do not claim to have invented all the parts, elements or steps described. Various modifications can be made in the construction, material, arrangement, and operation, and still be within the scope of my invention. The limits of the invention and the bounds of the patent protection are measured by and defined in the following claims. The restrictive description and drawing of the specific examples above do not point out what an infringement of this patent would be, but are to enable the reader to make and use the invention.

I claim as my invention:

1. An earthworking device comprising:

a. a frame,

b. hitch means on said frame for attaching the frame toa draft vehicle,

0. a pair of rippers attached to the frame,

d. an eccentric weight mounted on each ripper,

e. rotary means for rotating said weights about an axis aligned with the direction of draft,

f. said rotary means timed to rotate the weights in the same direction with one weight in a position of from the other weight,

g. a horizontal pin aligned with the direction of draft attached to each ripper,

h. a link pivoted to each pin so the rippers are substantially free to move vertically with respect to one another, but are restrained from movement horizontally to each other, and

j. down-pressure means for applying weight to the link,

k. said down-pressure means attached to the center of said link.

2. The invention as defined in claim 1 with additional limitations of m. said rippers spaced apart so the rippers may straddle a pipeline to be laid, and

n. a chute having i. rigid vertical sides and ii. a closable front,

iii. the bottom of the chute being about the same depth as the bottom of the ripper.

3. The invention as defined in claim 2 with added limitations of 0. said closable front having a V-shaped forward section,

p. each wing of said V-shaped forward section hinged to one of said rigid vertical sides,

q. power means for opening the closing said V- shaped section, so that r. the front may be opened to push the chute down over a pipeline laying on the ground and may be closed thereafter to open the ditch for operation.

4. The invention as defined in claim 3 with added limitations of s. a roller in the chute adapted to ride on top of the pipe, t. means for exerting downward pressure upon the roller and thus the pipe, and u. adjustment means for moving the roller to a different position. 5. A pipelaying machine comprising: a. a frame, b. hitch means on said frame for attaching the frame to a draft vehicle thereto, c. a pair of rippers attached to the frame d. with a space therebetween so that the rippers straddle a pipeline to be laid when in operation, and

e. a chute attached to the frame, f. the chute having i. rigid vertical sides and ii. a closable front, iii. the bottom of the chute being about the same depth as the bottom of the rippers. 6. The invention as defined in claim with added limitations of g. said closable front having a V-shaped forward section, h. each wing of said V-shaped forward section hinged to one of said rigid vertical sides, j. power means for opening and closing said V- shaped section, so that k. the front may be opened to push the chute down over a pipeline laying on the ground and may be closed thereafter to open the ditch for operation. 7. The invention as defined in claim 5 with added limitations of g. a roller in the chute adapted to ride on top of the pipe. h. means for exerting downward pressure upon the roller and thus the pipe, and j. adjustment means for moving the roller to a different position. 8. The invention as defined in claim 5 with added limitations of g. a roller at the forward portion of the chute near the top thereof, h. said roller as high as the top of said closable front so the pipe rides thereover. 9. The invention as defined in claim 5 with an added limitation of g. vibrating means for vibrating said rippers. 10. The invention as defined in claim 5 with added limitations of g. an eccentric weight mounted on each ripper, h. rotating means for rotating said weights about an axis aligned with the direction of draft, j. said rotary means timed to rotate the weights in the same direction with one weight always in a position of 180 from the other weight. 11. The invention as defined in claim 10 with an added limitation of k. interconnecting means between said rippers for maintaining the same horizontal spacing between said rippers while permitting vertical movement of either ripper. 12. The invention as defined in claim 10 with added limitations of k. a horizontal pivot pin aligned with the direction of draft attached to each ripper,

m. a link pivoted to each pin so the rippers are substantially free to move vertically with respect to one another, but are restrained from movement horizontally to each other.

13. The invention as defined in claim 5 with g. means for vibrating said rippers out of phase so the total result of vibration of each of the two rippers is in the vertical direction solely, and no resultant vibration of the two rippers together.

14. The invention as defined in claim 13 with added limitations of h. said closable front having a V-shaped forward section,

j. each wing of said V-shaped forward section hinged to one of said rigid vertical sides,

k. power means for opening and closing said V- shaped section, so that m. the front may be opened to push the chute down over a pipeline laying on the ground and may be closed thereafter to open the ditch for operation.

15. The invention as defined in claim 14 with added limitations of n. a roller in the chute adapted to ride on top of the pipe,

0. means for exerting downward pressure upon the roller and thus the pipe, and

p. adjustment means for moving the roller to a different position.

16. The invention as defined in claim 15 with added limitations of q. a roller at the forward portion of the chute near the top thereof,

r. said roller as high as the top of said closable front so the pipe rides thereover.

17. A method of laying a pipeline underground comprising:

a. laying the pipe i. on top of the ground ii. connected iii. along the path it is to be buried,

b. shattering the soil i. on either side of the pipe ii. to a depth it is to be laid,

0. opening a ditch by shoving the soil laterally from the path,

d. holding the ditch open by e. moving a chute along the ditch,

f. guiding the pipe into the ditch, and

g. allowing the ditch to close i. behind the chute ii. over the pipe.

18. The invention as defined in claim 17 wherein the step of shattering the soil is accomplished by h. drawing rippers through the soil on both sides of the pipeline.

19. The invention as defined in claim 18 with an added limitation of j. vibrating said rippers.

20. The invention as defined in claim 19 with an added limitation of k. vibrating said rippers out of phase to restrict th resultant vibration.

21. The invention as defined in claim 20 with an added limitation of m. pushing down upon the vibrating rippers.

22. The invention as definedin claim 17 with added limitations of 9 7 10 h. opening the front of the chute to'place the chute step of shattering the soil is accomplished by over the pipe laid on the ground, and m. drawing rippers through the soil on both sides of j. closing the front after it has been placed over the the pipeline, and

pipe whereby the closed front of the chute is the n. vibrating said rippers. means by which the ditch is opened. 25. The invention as defined in claim 24 with added 23. The invention as defined in claim 22 with an limitations of added limitation of o. vibrating said rippers out of phase to restrict the k. pushing the pipe downward into the ditch by an elresultant vibration, and

ement on the chute. p. pushing down upon the vibrating rippers. 24. The invention as defined in claim 23 wherein the 

1. An earthworking device comprising: a. a frame, b. hitch means on said frame for attaching the frame to a draft vehicle, c. a pair of rippers attached to the frame, d. an eccentric weight mounted on each ripper, e. rotary means for rotating said weights about an axis aligned with the direction of draft, f. said rotary means timed to rotate the weights in the same direction with one weight in a position of 180* from the other weight, g. a horizontal pin aligned with the direction of draft attached to each ripper, h. a link pivoted to each pin so the rippers are substantially free to move vertically with respect to one another, but are restrained from movement horizontally to each other, and j. down-pressure means for applying weight to the link, k. said down-pressure means attached to the center of said link.
 2. The invention as defined in claim 1 with additional limitations of m. said rippers spaced apart so the rippers may straddle a pipeline to be laid, and n. a chute having i. rigid vertical sides and ii. a closable front, iii. the bottom of the chute being about the same depth as the bottom of the Ripper.
 3. The invention as defined in claim 2 with added limitations of o. said closable front having a V-shaped forward section, p. each wing of said V-shaped forward section hinged to one of said rigid vertical sides, q. power means for opening the closing said V-shaped section, so that r. the front may be opened to push the chute down over a pipeline laying on the ground and may be closed thereafter to open the ditch for operation.
 4. The invention as defined in claim 3 with added limitations of s. a roller in the chute adapted to ride on top of the pipe, t. means for exerting downward pressure upon the roller and thus the pipe, and u. adjustment means for moving the roller to a different position.
 5. A pipelaying machine comprising: a. a frame, b. hitch means on said frame for attaching the frame to a draft vehicle thereto, c. a pair of rippers attached to the frame d. with a space therebetween so that the rippers straddle a pipeline to be laid when in operation, and e. a chute attached to the frame, f. the chute having i. rigid vertical sides and ii. a closable front, iii. the bottom of the chute being about the same depth as the bottom of the rippers.
 6. The invention as defined in claim 5 with added limitations of g. said closable front having a V-shaped forward section, h. each wing of said V-shaped forward section hinged to one of said rigid vertical sides, j. power means for opening and closing said V-shaped section, so that k. the front may be opened to push the chute down over a pipeline laying on the ground and may be closed thereafter to open the ditch for operation.
 7. The invention as defined in claim 5 with added limitations of g. a roller in the chute adapted to ride on top of the pipe. h. means for exerting downward pressure upon the roller and thus the pipe, and j. adjustment means for moving the roller to a different position.
 8. The invention as defined in claim 5 with added limitations of g. a roller at the forward portion of the chute near the top thereof, h. said roller as high as the top of said closable front so the pipe rides thereover.
 9. The invention as defined in claim 5 with an added limitation of g. vibrating means for vibrating said rippers.
 10. The invention as defined in claim 5 with added limitations of g. an eccentric weight mounted on each ripper, h. rotating means for rotating said weights about an axis aligned with the direction of draft, j. said rotary means timed to rotate the weights in the same direction with one weight always in a position of 180* from the other weight.
 11. The invention as defined in claim 10 with an added limitation of k. interconnecting means between said rippers for maintaining the same horizontal spacing between said rippers while permitting vertical movement of either ripper.
 12. The invention as defined in claim 10 with added limitations of k. a horizontal pivot pin aligned with the direction of draft attached to each ripper, m. a link pivoted to each pin so the rippers are substantially free to move vertically with respect to one another, but are restrained from movement horizontally to each other.
 13. The invention as defined in claim 5 with g. means for vibrating said rippers out of phase so the total result of vibration of each of the two rippers is in the vertical direction solely, and no resultant vibration of the two rippers together.
 14. The invention as defined in claim 13 with added limitations of h. said closable front having a V-shaped forward section, j. each wing of said V-shaped forward section hinged to one of said rigid vertical sides, k. power means for opening and closing said V-shaped section, so that m. the front may be opened to push the chute down over a pipeline laying on the ground and may be closed thereafter to open thE ditch for operation.
 15. The invention as defined in claim 14 with added limitations of n. a roller in the chute adapted to ride on top of the pipe, o. means for exerting downward pressure upon the roller and thus the pipe, and p. adjustment means for moving the roller to a different position.
 16. The invention as defined in claim 15 with added limitations of q. a roller at the forward portion of the chute near the top thereof, r. said roller as high as the top of said closable front so the pipe rides thereover.
 17. A method of laying a pipeline underground comprising: a. laying the pipe i. on top of the ground ii. connected iii. along the path it is to be buried, b. shattering the soil i. on either side of the pipe ii. to a depth it is to be laid, c. opening a ditch by shoving the soil laterally from the path, d. holding the ditch open by e. moving a chute along the ditch, f. guiding the pipe into the ditch, and g. allowing the ditch to close i. behind the chute ii. over the pipe.
 18. The invention as defined in claim 17 wherein the step of shattering the soil is accomplished by h. drawing rippers through the soil on both sides of the pipeline.
 19. The invention as defined in claim 18 with an added limitation of j. vibrating said rippers.
 20. The invention as defined in claim 19 with an added limitation of k. vibrating said rippers out of phase to restrict the resultant vibration.
 21. The invention as defined in claim 20 with an added limitation of m. pushing down upon the vibrating rippers.
 22. The invention as defined in claim 17 with added limitations of h. opening the front of the chute to place the chute over the pipe laid on the ground, and j. closing the front after it has been placed over the pipe whereby the closed front of the chute is the means by which the ditch is opened.
 23. The invention as defined in claim 22 with an added limitation of k. pushing the pipe downward into the ditch by an element on the chute.
 24. The invention as defined in claim 23 wherein the step of shattering the soil is accomplished by m. drawing rippers through the soil on both sides of the pipeline, and n. vibrating said rippers.
 25. The invention as defined in claim 24 with added limitations of o. vibrating said rippers out of phase to restrict the resultant vibration, and p. pushing down upon the vibrating rippers. 